If it's not a failure, MS doesn't do much to assure it's not. Hiding sales numbers, weird statistics in PR statements. It depends on how much Live takes in I guess. But, I've never seen a company throw the kitchen sink at a product to try and turn it around like MS. They try everything, and most times, the needle doesn't even move. It's unprecedented, and likely costly.

Compared to 360 obviously yes. Also I  don't think it is a good idea to compare it to Genesis or N64 in terms of sales. The whole console market was not as big as it is today back in the 90s.

It's a success and still has around 3 or 4 more years left with support so I can see it selling 60 something million. A drop from the 360 but definitely not a failure like the Wii U, Vita and dre.am

What about AU, NZ and South America? 

Nope just a good console with mediocre performance power and saleswise which has a bit too few AAA exclusives.

If Microsoft is making money out of it then no.

Overall yes I consider it a failure. You have to remember 360 had a 19million lead over Sony in the US. Now they aren't even ahead of Sony at all and most likely never will be. That means they've lost a massive amount of sales. So in the grand scheme of things yes a massive failure if you ask me.

It depends what Microsoft expected out of it. If it fell short of those expectations, then yes, it's a failure. But I'm not sure if they ever said what their projections were.

you think it will sell more, or at least as much, in it's second 4-year period compared to it's first?